Equilibrium and kinetics of adsorption of Ca(Ⅱ) ions onto KCTS and HKCTS

来源期刊：中南大学学报(英文版)2010年第2期

论文作者：丁萍 黄可龙 杨桦 李桂银 刘艳飞

文章页码：277 - 284

Key words：chitosan α-ketoglutaric acid; hydroxamated chitosan α-ketoglutaric acid; Ca(Ⅱ) ions; adsorption kinetics

Abstract: The adsorption of Ca(Ⅱ) ions from aqueous solution by chitosan α-ketoglutaric acid (KCTS) and hydroxamated chitosan α-ketoglutaric acid (HKCTS) was studied in a batch adsorption system. The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms, and isotherm constants were determined. The kinetics of the adsorption with respect to the initial Ca(Ⅱ) ions concentration, temperature and pH was investigated. The pseudo-first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The results show that the experimental data fit well to the Langmuir isotherms with a high correlation coefficient (R²). The pseudo-second-order rate expression provides the best fitting kinetic model. The pseudo second-order kinetic model is indicated with the activation energy of 26.22 kJ/mol and 6.16 kJ/mol for KCTS and HKCTS, respectively. It is suggested that the overall rate of adsorption of Ca(Ⅱ) ions is likely to be controlled by the chemical process.

基金信息：the National Natural Science Foundation of China